Chronic pulmonary disease will be studied using the monkey-Histoplasma model. Cavitary histoplasmosis has been produced in rhesus monkeys infected intratracheally. An initial observation was made that delayed hypersensitivity develops simultaneously in both cavitary and noncavitary animals; however, antibody production is delayed in those animals developing pulmonary cavities. The objectives of this proposal are: (1) To confirm the observation that delayed hypersensitivity appears at the same time in both cavitary and noncavitary animals; (2) To determine the onset of antibody production in both groups; (3) To determine the quality (Ig class) of antibody production in both groups; (4) To accurately detect the onset of pulmonary cavitation.